Function: LOOKUP-PACKAGE

Source

(defun lookup-package (ns env)
  (declare (special uri-to-package))
  (if ns
      (or (cdr (assoc (or (lookup-namespace ns env)
                          (error 'reference-to-undeclared-namespace :namespace ns))
                      uri-to-package :test #'string=))
          (error 'reference-to-undeclared-namespace :namespace ns))
      *package*))